Puz­zle:
Marie, Claude, and Jean are in a com­pe­ti­tion. Here are their results:
  1. The youngest per­son received the least points.
  2. Claude got half of the points of the eldest.
  3. Jean received as many points as both oth­ers combined.
Ques­tion:
Who is the eldest ?
The Brain Exer­cise:
This puz­zle uses plan­ning and rea­son­ing skills. You read the state­ments and then must develop a plan to solve the prob­lem using your rea­son­ing skills. These skills are found pre­dom­i­nantly in your pre­frontal cor­tex. This area of your brain is respon­si­ble for exec­u­tive func­tions such as plan­ning, struc­tur­ing, and eval­u­at­ing vol­un­tary, goal-directed behav­ior, i.e., activ­i­ties requir­ing the con­stant com­par­i­son of planned acts with the effects achieved.
If you’ve already got the puz­zle fig­ured out, click on the link below to find the answer.
Solu­tion:
Start with state­ment #2 which tells us that Claude is not the eldest. So the eldest must be either Marie or Jean. State­ment #3 tells us that Jean received the sum of the other two people’s points, and those point totals are not equal, per state­ment #1 (the youngest has less points than the other two). For Jean to be the eldest, Claude and Marie would each have half of the points of Jean has, but we know they can’t have the same amount of points. There­fore, Jean must have the most points, and Claude must be the youngest, but Marie is the eldest.